PHOSPHOROUS-CONTAINING COMPOUND, APPLICATION THEREOF, AND METHOD FOR PREPARING THE SAME

Abstract

A phosphorous-containing compound is represented by Formula (I):

##STR00001## wherein n is an integer ranging from 1 to 4; R.sup.1 represents hydrogen or a linear or branched C.sub.1-C.sub.4 alkyl group, and a plurality of R.sup.1s are the same or different when n is larger than 1; R.sup.2 represents hydrogen,

##STR00002##

wherein Ep is an epoxy resin moiety; or

##STR00003##

represents

##STR00004##

wherein Ar represents a linear or branched C.sub.1-C.sub.12 alkyl group or a C.sub.6-C.sub.12 aryl group; and R.sup.3 represents hydrogen or methyl.

Claims

1. A phosphorous-containing compound represented by Formula (I): ##STR00025## wherein n is an integer ranging from 1 to 4; R.sup.1 represents hydrogen or a linear or branched C.sub.1-C.sub.4 alkyl group, and a plurality of R.sup.1s are the same or different when n is larger than 1; R.sup.2 represents hydrogen, ##STR00026## wherein Ep is an epoxy resin moiety; or ##STR00027## represents ##STR00028## wherein Ar represents a linear or branched C.sub.1-C.sub.12 alkyl group or a C.sub.6-C.sub.12 aryl group; and R.sup.3 represents hydrogen or methyl.

2. The phosphorous-containing compound according to claim 1, wherein R.sup.2 represents hydrogen.

3. The phosphorous-containing compound according to claim 1, wherein R.sup.1 represents hydrogen.

4. The phosphorous-containing compound according to claim 1, wherein R.sup.3 represents hydrogen.

5. The phosphorous-containing compound according to claim 1, wherein Ar represents phenyl.

6. The phosphorous-containing compound according to claim 1, wherein said epoxy resin moiety is derived from a resin selected from the group consisting of a novolac epoxy resin, a bisphenol A epoxy resin, a bisphenol F epoxy resin, an aliphatic epoxy resin, and a glycidyl amine resin.

7. A flame-retardant resin composition, comprising the phosphorous-containing compound according to claim 1 and a resin.

8. A cured flame-retardant resin obtained by curing the flame-retardant resin composition according to claim 7.

9. A method for preparing the phosphorous-containing compound according to claim 1, comprising the step of: subjecting a p-hydroxy benzoyl derivative of Formula (II) and an oxa-phosphaphenanthrene oxide of Formula (III) to a reaction at a temperature ranging from 190 to 250 C. in the absence of a solvent, ##STR00029## ##STR00030## wherein n, R.sup.1 and R.sup.3 are the same as those defined in claim 1, and a molar ratio of the p-hydroxy benzoyl derivative to the oxa-phosphaphenanthrene oxide ranges from 1:2 to 1:5.5.

10. The method according to claim 9, wherein the temperature ranges from 200 to 220 C.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Other features and advantages of the disclosure will become apparent in the following detailed description of the embodiment(s) with reference to the accompanying drawings, of which:

[0030] FIG. 1 is a .sup.1H NMR spectrum of a phosphorous-containing compound P1 obtained in an illustrated example; and

[0031] FIG. 2 is a mass spectrum of the phosphorous-containing compound P1.

DETAILED DESCRIPTION

[0032] The phosphorous-containing compound of the disclosure is represented by Formula (I):

##STR00015##

[0033] wherein

[0034] n is an integer ranging from 1 to 4;

[0035] R.sup.1 represents hydrogen or a linear or branched C.sub.1-C.sub.4 alkyl group, and a plurality of R.sup.1s are the same or different when n is larger than 1;

[0036] R.sup.2 represents hydrogen,

##STR00016##

wherein Ep is an epoxy resin moiety; or

##STR00017##

represents

##STR00018##

wherein Ar represents a linear or branched C.sub.1-C.sub.12 alkyl group or a C.sub.6-C.sub.12 aryl group; and

[0037] R.sup.3 represents hydrogen or methyl.

[0038] In certain embodiments, R.sup.2 represents hydrogen.

[0039] In certain embodiments, R.sup.1 represents hydrogen.

[0040] In certain embodiments, R.sup.3 represents hydrogen.

[0041] In certain embodiments, Ar represents phenyl.

[0042] In certain embodiments, the epoxy resin moiety is derived from a resin selected from the group consisting of a novolac epoxy resin, a bisphenol A epoxy resin, a bisphenol F epoxy resin, an aliphatic epoxy resin, and a glycidyl amine resin.

[0043] In the illustrated example, the epoxy resin moiety is derived from a cresol-novolac epoxy resin.

[0044] The flame-retardant resin composition of the disclosure includes the phosphorous-containing compound and a resin.

[0045] In certain embodiments, the resin contained in the flame-retardant resin composition of the disclosure is a thermosetting resin.

[0046] The cured flame-retardant resin of the disclosure is obtained by curing the flame-retardant resin composition.

[0047] The method for preparing the phosphorous-containing compound of the disclosure includes the step of:

[0048] subjecting a p-hydroxy benzoyl derivative of Formula (II) and an oxa-phosphaphenanthrene oxide of Formula (III) to a reaction at a temperature ranging from 190 to 250 C. in the absence of a solvent,

##STR00019##

[0049] wherein

##STR00020##

[0050] n, R.sup.1 and R.sup.3 are the same as those defined for the phosphorous-containing compound represented by Formula (I), and

[0051] a molar ratio of the p-hydroxy benzoyl derivative to the oxa-phosphaphenanthrene oxide ranges from 1:2 to 1:5.5.

[0052] In certain embodiments, the p-hydroxy benzoyl derivative of Formula (II) and the oxa-phosphaphenanthrene oxide of Formula (III) are subjected to to a reaction at a temperature ranging from 200 to 220 C.

[0053] The following examples are provided to illustrate the embodiments of the disclosure, and should not be construed as limiting the scope of the disclosure.

EXAMPLES

Synthesis of Phosphorous-Containing Compounds P1-P4

Synthesis Example 1

[0054] DOPO (630 g, 2.92 mol) was heated at 150 for 1 hour to remove water therefrom, followed by addition of 4-hydroxybenzaldehyde (70 g, 0.57 mol) thereinto to conduct a reaction at 200 C. under a nitrogen atmosphere for 3 hours to obtain a phosphorous-containing compound P1. The scheme for the reaction in Synthesis Example 1 is shown below.

##STR00021##

[0055] As shown in the scheme, the phosphorous-containing compound P1 includes one phenyl group having a reactive group (i.e., OH) and two DOPO moieties. The phosphorous content of the phosphorous-containing compound P1 is 11.55 wt %. The .sup.1H NMR spectrum and the mass spectrum of the phosphorous content of the phosphorous-containing compound P1 are shown in FIG. 1 and FIG. 2, respectively.

Synthesis Example 2

[0056] The phosphorous-containing compound P1 (53.6 g, 0.1 mole) and epichlorohydrin (170 g, 1.8 mol) were added into a reaction vessel, and were reacted under reflux for 6 hours to recover unreacted epichlorohydrin, followed by addition of toluene, water washing, and drying to obtain a phosphorous-containing compound P2. The scheme for the reaction in Synthesis Example 2 is shown below.

##STR00022##

[0057] As shown in the scheme, the phosphorous-containing compound P2 includes one phenyl group having a reactive group (i.e., an epoxy group) and two DOPO moieties.

Synthesis Example 3

[0058] The phosphorous-containing compound P1 (53.6 g, 0.1 mole), aniline (9.3 g, 0.1 mol), and para-formaldehyde (3.0 g, 0.1 mol) were added into a reaction vessel, and were reacted at 110 C. for 3 hours, followed by addition of chloroform (500 ml). An organic phase was collected after washing with an aqueous NaOH solution (1N) and pure water. A phosphorous-containing compound P3 was obtained after removing the solvent from the organic phase. The scheme for the reaction in Synthesis Example 3 is shown below.

##STR00023##

[0059] As shown in the scheme, the phosphorous-containing compound P3 includes one benzoxazine group and two DOPO moieties.

Synthesis Example 4

[0060] The phosphorous-containing compound P1 (53.6 g, 0.1 mole) and a cresol-novolac epoxy resin (34 g, 1.8 mol) were dissolved into methyl isobutyl ketone (800 ml), followed by addition of triphenyl phosphine (0.6 g) and a reaction under reflux for 3 hours. A phosphorous-containing compound P4 was obtained after removing the solvent. The scheme for the reaction in Synthesis Example 4 is shown below.

##STR00024##

[0061] As shown in the scheme, the phosphorous-containing compound P4 includes two DOPO moieties and one phenyl group linking an epoxy resin moiety.

Application Examples 1-4 and Comparative Application Example 1

Preparation of Flame-Retardant Resin Composition and Flame-Retardant Resin

[0062] Diglycidyl of bisphenol A (DGEBA, epoxy equivalent: 188 g/mol), dicyanodiamide (DICY), and the phosphorous-containing compound P1 were formulated in methyl ethyl ketone using the amounts shown in Table 1 below to obtain flame-retardant resin compositions of Application Examples 1-4 and a resin composition of Comparative Application Example 1, each of which was cured by sequential heating at 160 C. for 1 hour, at 190 C. for 2 hours, and at 200 C. for 2 hours, thereby obtaining cured flame-retardant resins E1-E4 and cured resin CE. The phosphorous contents of the cured flame-retardant resins E1-E4 and the cured resin CE were respectively determined using elemental analysis. Td5 (degradation temperature at 5% weight loss) of each of the cured flame-retardant resins E1-E4 and the cured resin CE was determined using thermogravimetric analysis under atmosphere. The flammability rating of each of the cured flame-retardant resins E1-E4 and the cured resin CE was determined using a UL-94 flame rating test method. The results are shown in Table 1.

TABLE-US-00001 TABLE 1 Phosphorous Flammability DGEBA DICY P1 Contents T.sub.d Rating Resins (phr) (phr) (phr) (wt %) ( C.) (UL 94) E1 100 7 5 0.52 321 V1 E2 100 7 10 0.99 317 V0 E3 100 7 15 1.42 312 V0 E4 100 7 20 1.82 320 V0 CE 100 7 0 0 319 Failed

[0063] As shown in Table 1, the flame retardance of the cured flame-retardant resin may be enhanced by the phosphorous-containing compound of the disclosure while satisfactory thermal stability may be attained for the cured flame-retardant resin containing the phosphorous-containing compound of the disclosure.

[0064] In view of the aforesaid, the phosphorous-containing compound of the disclosure includes two DOPO moieties and one phenyl group having a reactive group and has relatively high phosphorous content. The flame retardance and the thermal stability of the cured resin may be enhanced by containing the phosphorous-containing compound of the disclosure therein.

[0065] In the description above, for the purposes of explanation, numerous specific details have been set forth in order to provide a thorough understanding of the embodiment(s). It will be apparent, however, to one skilled in the art, that one or more other embodiments may be practiced without some of these specific details. It should also be appreciated that reference throughout this specification to one embodiment, an embodiment, an embodiment with an indication of an ordinal number and so forth means that a particular feature, structure, or characteristic may be included in the practice of the disclosure. It should be further appreciated that in the description, various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of various inventive aspects.

[0066] While the disclosure has been described in connection with what is (are) considered the exemplary embodiment(s), it is understood that this disclosure is not limited to the disclosed embodiment(s) but is intended to cover various arrangements included within the spirit and scope of the broadest interpretation so as to encompass all such modifications and equivalent arrangements.